Aluminum electrolytic capacitor

ABSTRACT

An aluminum-electrolyte capacitor assembly is provided which includes a capacitor disposed in a metallic housing. The housing is accommodated and held by a ring clamp. The ring clamp is attached to a mounting plate, preferably by screw fasteners. The mounting plate includes a bore for accommodating at least part of the housing. The ring clamp includes a conically shaped extension that extends downward and mateably engages the bore. The assembly may also include a protective ring disposed in the bore and sandwiched between the conically shaped extension of the ring clamp and the mounting plate.

FIELD OF THE INVENTION

The invention is directed to an aluminum-electrolyte capacitor,particularly for employment in capacitor batteries, that is installed ina metallic housing, and whereby the housing is held by a ring clampscrewed to a mounting plate.

BACKGROUND OF THE INVENTION

Ring clamp fastenings are known, for example, from the SiemensMatsushita Components Datenbuch 1997, “Aluminum-Electrolyte Capacitors”,pages 142 through 145.

Given these known ring clamp fastenings, the housing is fixed in thering clamp with tension screws and nuts, and the ring clamp itself isthen connected to a mounting plate with a screwed connection. Such afastening of a capacitor to the housing jacket, however, isproblematical because the wall thicknesses of the housing jackets aregenerally very low, and the material is composed of relatively softaluminum.

SUMMARY OF THE INVENTION

An object of the present invention is to specify an aluminum-electrolytecapacitor of the species initially cited that is secured in mechanicallystable fashion on a mounting plate without having significant tensionforces acting on the housing.

This object is inventively achieved in that a conically fashioned partis arranged at the ring clamp, said part engaging into a bore attachedto the mounting plate.

In an embodiment, the present invention provides an aluminum-electrolytecapacitor assembly that comprises an aluminum-electrolyte capacitordisposed in a metallic housing, the housing being accommodated in andheld by a ring clamp, the ring clamp being attached to a mounting plate,the mounting plate comprising a bore for accommodating at least part ofthe housing, the ring clamp comprising a conically shaped extension thatmateably engages the bore.

In an embodiment, the ring clamp is attached to the mounting plate byway of at least on screw.

In an embodiment, the conically shaped extension comprises at least oneslot.

In an embodiment, the ring clamp is fabricated from an insulatingmaterial.

In an embodiment, the present invention further comprises a protectivering disposed in the bore and sandwiched between conically shapedextension and mounting plate.

In an embodiment, the protective ring is fabricated from plastic.

In an embodiment, the protective ring is conically shaped for receivingthe conically shaped extension.

Other objects and advantages of the present invention will becomeapparent from reading the following detailed description and appendedclaims, and upon reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

Advantageous developments are the subject matter of subclaims.

The invention is explained in greater detail below with reference to theDrawing, wherein:

FIG. 1 is a side view of a capacitor secured in a mounting plate,

FIG. 2 is a plan view of the capacitor shown in FIG. 1,

FIG. 3 is a side elevational view of the ring clamp, and

FIG. 4 is a bottom plan view of the ring clamp of FIG. 3.

It should be understood that the drawings are not necessarily to scaleand that the embodiments are sometimes illustrated by graphic symbols,phantom lines, diagrammatic representations and fragmentary views. Incertain instances, details which are not necessary for an understandingof the present invention or which render other details difficult toperceive may have been omitted. It should be understood, of course, thatthe invention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1 shows the housing 1 of an aluminum-electrolyte capacitor 11 thathas its terminals 2 secured to a busbar 3. Separate interconnects forthe oppositely polled terminals 2, which are not shown, are therebyarranged in the Figure.

The capacitor housing 1 is fixed by a ring clamp 5 that is connected toa mounting plate 4 with screws 6. The ring clamp 5 is composed of aninsulating material, for example plastic, and has a conically shapedpart 7 that engages into a mounting bore 8 defined by the mounting plate4.

When screwing the ring clamp 5 to the mounting plate 4, the conical part7 is pulled into the mounting bore 8. Due to the diminution in thediameter of the cone part 7 that thereby ensues, a fastening that isextremely mechanically stable ensues, whereby the tension forces areintroduced directly into the mounting plage 4. Slots 12 (see FIGS. 3 and4) can Thereby be arranged in the cone part 7 for promoting thediminution in diameter.

What the described embodiment achieves is that the bending stresses thatare particularly critical given plastics are considerably reduced in thering clamp 5 due to this type of mounting, these bending stressesoccurring, for example, given vibrating stress of the assembly.

Given metallic mounting plates 4, a protective ring 9 is arrangedbetween conical part 7 and mounting plate 4 in order to avoid notchingdanger and as a definition of the hole edge, this protective ring 9being preferably composed of plastic and being conically fashioned atits inside 10.

Given mounting plates 4 of plastic or given a rounded-off hole edge,this protective ring can be omitted.

Diameter tolerances of the capacitor housing 1 can be compensated by theconically fashioned part 7, whereby the range of the tolerancecompensation is defined by the angle and the length of the cone. Asalready described, the conical region 7 of the ring clamp 5 can beinterrupted by preferably two through four slots, whereby, of course,more slots can also be arranged.

A further advantage given the fastening of the capacitor housing 1 witha ring clamp 5 of the invention is comprised therein that lengthtolerances of the capacitor housing 1 can also be compensated, thisbeing particularly important given capacitor batteries.

The clamping forces are thereby primarily absorbed by the mounting plate4 and not by the ring clamp 5.

FIG. 2 shows a plan view onto the capacitor housing 1 without a busbar.The ring clamp 5 is thereby connected to the mounting plate with twoscrews 6. Alternatively, the screwed connection can also ensue at morepoints, for example three or four.

From the above description, it is apparent that the objects of thepresent invention have been achieved. While only certain embodimentshave been set forth, alternative embodiments and various modificationswill be apparent from the above description to those skilled in the art.These and other alternatives are considered equivalents and within thespirit and scope of the present invention.

What is claimed is:
 1. An aluminum-electrolyte capacitor assemblycomprising: an aluminum-electrolyte capacitor disposed in a metallichousing, the housing being accommodated in and held by a ring clamp, thering clamp being attached to a mounting plate, the mounting platecomprising a bore for accommodating at least part of the housing, thering clamp comprising a conically shaped extension that mateably engagesthe bore.
 2. The assembly of claim 1 wherein the ring clamp is attachedto the mounting plate by way of at least on screw.
 3. The assembly ofclaim 1 wherein the conically shaped extension comprises at least oneslot.
 4. The assembly of claim 1 wherein the ring clamp is fabricatedfrom an insulating material.
 5. The assembly of claim 1 furthercomprising a protective ring disposed in the bore and sandwiched betweenthe conically shaped extension and the mounting plate.
 6. The assemblyof claim 5 wherein the protective ring is fabricated from plastic. 7.The assembly of claim 5 wherein the protective ring is conically shapedfor receiving the conically shaped extension.
 8. An aluminum-electrolytecapacitor assembly comprising: an aluminum-electrolyte capacitordisposed in a metallic housing, the housing being accommodated in andheld by a ring clamp, the ring clamp being fabricated from an insulatingmaterial, the ring clamp being attached to a mounting plate with atleast one screw, the mounting plate comprising a bore for accommodatingat least part of the housing, the ring clamp comprising a conicallyshaped extension that mateably engages the bore, the assembly furthercomprising a protective ring disposed in the bore and sandwiched betweenthe ring clamp and the mounting plate.
 9. The assembly of claim 8wherein the conically shaped extension comprises at least one slot. 10.The assembly of claim 8 wherein the protective ring is fabricated fromplastic.
 11. The assembly of claim 10 wherein the protective ring isconically shaped for receiving the conically shaped extension.